The present invention provides an electrical power system comprising a plurality of battery modules in series connection between adjacent battery modules, wherein each of the battery modules comprises a positive male terminal, a negative male terminal, and a socket corresponding to each of the positive male terminals and the negative male terminals. The connectors connecting the adjacent battery modules include a sequence tab that provides an irreversible engagement sequence of the connectors into the sockets of the adjacent battery modules. The irreversible engagement sequence positions an insulating portion of the connectors housing on each positive male terminal of the battery modules that are in series connection in order to isolate the positive male terminals from human contact. The present invention also provides a female terminal including a canted coil spring positioned within a stamped groove that may be housed within the above-described connectors.